David Wicks, 55, of Westergate, admitted nine counts of indecent assault, which happened during his employment at Swindon’s Wyvern Theatre.
Detective Constable Mike Armishaw from Swindon CID said: “I want to highlight the bravery of the victims who came forward after all these years, who had the full confidence to stand up and give evidence with the support of the police and the criminal justice system.
“I hope this sentence gives them some form of closure so they are able to move on with their lives.
“His pattern of offending demonstrated that he was able to manipulate situations to his advantage and was extremely calculated in doing so.
“David Wicks’ guilty plea reflects the overwhelming level of evidence that he was faced with.”